The San Francisco Chronicle reports that California has taken the first step in the nation toward setting maximum drinking-water levels for the cancer-causing chemical made famous by the 2000 film "Erin Brockovich."  After a controversial decade of study on the health effects of hexavalent chromium, or chromium 6, the California Office of Environmental Health Hazard Assessment on Thursday proposed a level of 0.06 parts per billion for the heavy metal. Regular drinking water exposure below that level would qualify as "negligible risk," according to researchers.

The proposal, which is subject to further review and public comment, is not an enforceable standard. However, it represents the initial step in developing a statewide chromium 6 ceiling for drinking water under the Department of Public Health - a criteria probably several years in the making. That, in turn, would give authorities the power to order cleanup of contaminated drinking water sources.  Currently, California and the United States have maximums for total chromium, which includes chromium 6 as well as other benign chromium variants.